Connectomics
Encyclopedia
Connectomics is a high-throughput
application of neural imaging and histological
techniques in order to increase the speed, efficiency, and resolution of maps of the multitude of neural connections in a nervous system
. The principal focus of such a project is the brain, although any neural connections could theoretically be mapped by connectomics, including, for example, neuromuscular junctions. The map produced by such a project is called a connectome
.
. The main tool for connectomics research at the microscale level is 3D electron microscopy. To see one of the first micro-connectomes at full-resolution, visit the Open Connectome Project, which is hosting several connectome datasets, including the 12TB dataset from Bock et al. (2011).
, some of the model systems used for connectomics research are the mouse
, the fruit fly
, the nematode
C. elegans
, and the barn owl
.
, and potential therapies for them. Generally, the field of neuroscience
would benefit from standardization and raw data. For example, connectome maps can be used to inform computational models of whole-brain dynamics. Current neural networks mostly rely on probabilistic representations of connectivity patterns.
Others have criticized attempts towards a microscale connectome, arguing that we don't have enough knowledge about where to look for insights, or that it cannot be completed within a realistic time frame.
initially faced many of the above criticisms, but was nevertheless completed ahead of schedule and has led to many advances in genetics. Some have argued that analogies can be made between genomics and connectomics, and therefore we should be at least slightly more optimistic about the prospects in connectomics.
High-throughput
High-throughput may refer to:* High-throughput computing - a computer science concept * High-throughput screening - a bioinformatics concept* Measuring data throughput - a communications concept...
application of neural imaging and histological
Histology
Histology is the study of the microscopic anatomy of cells and tissues of plants and animals. It is performed by examining cells and tissues commonly by sectioning and staining; followed by examination under a light microscope or electron microscope...
techniques in order to increase the speed, efficiency, and resolution of maps of the multitude of neural connections in a nervous system
Nervous system
The nervous system is an organ system containing a network of specialized cells called neurons that coordinate the actions of an animal and transmit signals between different parts of its body. In most animals the nervous system consists of two parts, central and peripheral. The central nervous...
. The principal focus of such a project is the brain, although any neural connections could theoretically be mapped by connectomics, including, for example, neuromuscular junctions. The map produced by such a project is called a connectome
Connectome
A connectome is a comprehensive map of neural connections in the brain.The production and study of connectomes, known as connectomics, may range in scale from a detailed map of the full set of neurons and synapses within part or all of the nervous system of an organism to a macro scale description...
.
Tools
One of the main tools used for connectomics research at the macroscale level is diffusion MRIDiffusion MRI
Diffusion MRI is a magnetic resonance imaging method that produces in vivo images of biological tissues weighted with the local microstructural characteristics of water diffusion, which is capable of showing connections between brain regions...
. The main tool for connectomics research at the microscale level is 3D electron microscopy. To see one of the first micro-connectomes at full-resolution, visit the Open Connectome Project, which is hosting several connectome datasets, including the 12TB dataset from Bock et al. (2011).
Model Systems
Aside from the human brainHuman brain
The human brain has the same general structure as the brains of other mammals, but is over three times larger than the brain of a typical mammal with an equivalent body size. Estimates for the number of neurons in the human brain range from 80 to 120 billion...
, some of the model systems used for connectomics research are the mouse
Mouse
A mouse is a small mammal belonging to the order of rodents. The best known mouse species is the common house mouse . It is also a popular pet. In some places, certain kinds of field mice are also common. This rodent is eaten by large birds such as hawks and eagles...
, the fruit fly
Fruit fly
Fruit fly may refer to several organisms:* Tephritidae, a family of large, colorfully marked flies including agricultural pests* Drosophilidae, a family of smaller flies, including:** Drosophila, the genus of small fruit flies and vinegar flies...
, the nematode
Nematode
The nematodes or roundworms are the most diverse phylum of pseudocoelomates, and one of the most diverse of all animals. Nematode species are very difficult to distinguish; over 28,000 have been described, of which over 16,000 are parasitic. It has been estimated that the total number of nematode...
C. elegans
Caenorhabditis elegans
Caenorhabditis elegans is a free-living, transparent nematode , about 1 mm in length, which lives in temperate soil environments. Research into the molecular and developmental biology of C. elegans was begun in 1974 by Sydney Brenner and it has since been used extensively as a model...
, and the barn owl
Barn Owl
The Barn Owl is the most widely distributed species of owl, and one of the most widespread of all birds. It is also referred to as Common Barn Owl, to distinguish it from other species in the barn-owl family Tytonidae. These form one of two main lineages of living owls, the other being the typical...
.
Applications
By comparing diseased connectome and healthy connectomes, we should gain insight into certain psychopathologies, such as neuropathic painNeuropathic pain
Neuropathic pain results from lesions or diseases affecting the somatosensory system. It may be associated with abnormal sensations called dysesthesia, which occur spontaneously and allodynia that occurs in response to external stimuli. Neuropathic pain may have continuous and/or episodic ...
, and potential therapies for them. Generally, the field of neuroscience
Neuroscience
Neuroscience is the scientific study of the nervous system. Traditionally, neuroscience has been seen as a branch of biology. However, it is currently an interdisciplinary science that collaborates with other fields such as chemistry, computer science, engineering, linguistics, mathematics,...
would benefit from standardization and raw data. For example, connectome maps can be used to inform computational models of whole-brain dynamics. Current neural networks mostly rely on probabilistic representations of connectivity patterns.
Criticism
The use of the word -omics to describe this system has been criticized. The coinage of the word is seen in two sources, in an article by Olaf Sporns and a PhD thesis by Patric Hagmann.Others have criticized attempts towards a microscale connectome, arguing that we don't have enough knowledge about where to look for insights, or that it cannot be completed within a realistic time frame.
Comparison to genomics
The human genome projectHuman Genome Project
The Human Genome Project is an international scientific research project with a primary goal of determining the sequence of chemical base pairs which make up DNA, and of identifying and mapping the approximately 20,000–25,000 genes of the human genome from both a physical and functional...
initially faced many of the above criticisms, but was nevertheless completed ahead of schedule and has led to many advances in genetics. Some have argued that analogies can be made between genomics and connectomics, and therefore we should be at least slightly more optimistic about the prospects in connectomics.
External links
- Open Connectome Project
- The Connectome Project at Harvard
- Connectome Research by EPFL/CHUV, Lausanne, Switzerland
- The NIH Blueprint for Neuroscience Research
- TEDTED (conference)TED is a global set of conferences owned by the private non-profit Sapling Foundation, formed to disseminate "ideas worth spreading"....
talk by Sebastian SeungSebastian SeungSebastian Seung is a Korean American multi-disciplinary expert whose research efforts have spanned the fields of neuroscience, physics and bioinformatics. He is a professor of Computational Neuroscience in the Department of Brain and Cognitive Sciences and a professor of Physics at the...
: "I am my connectome".